Is 89 a prime number.... If not what is 89/100 in simplest form?

Question

Is 89 a prime number.... If not what is 89/100 in simplest form?

Answer 1

Yes 89 is definitly a prime number trust me

Answer 2

89 is indeed prime, but I had to respond to "sunshine's" idea that odd numbers are prime and even numbers aren't.

The only even number that IS prime is two - all other even numbers can be divided by (at least) two.  An odd number is not necessarily prime (examples of non-prime odd numbers are 27 and 35).

I usually start by trying to divide the number by 2, then 3, until I reach a point where  two consecutive integers multiplied together (like 9 * 10) put me OVER the target number (because any higher integers would have to be multiplied by something lower, if that makes sense).  If the number is odd (like 89 is), you can also skip over all the other even integers, because an even number multiplied by ANY other integer will ALWAYS be even.

So with 89 as the example: is it divisible by

2? - no

3? - no

4? - no, because 89 is odd

5? - no

6? - no, because 89 is odd

7? - no

8? - no, because 89 is odd

9? - no

10? - no, because 89 is odd

If I multiply 9 x 10, that's 90 which is above 89.  11 would have to be multiplied by something lower than 9 or 10, and I've already tried all of them, so the number must be prime.

Answer 3

yes it is.

p.s:

the key to knowing that is if the second # is odd its prime and if its an even # it is not prime.It;s 100% sure to work.=]

Answer 4

My son says that it is. He knows a lot more than I do.